lung volumes

TLC

Total lung capacity: the volume in the lungs at maximal inflation, the sum of VC and RV.

TV/VT

Tidal volume: that volume of air moved into or out of the lungs in 1 breath (TV indicates a subdivision of the lung; when tidal volume is precisely measured, as in gas exchange calculation, the symbol TV or VT is used.)

RV

Residual volume: the volume of air remaining in the lungs after a maximal exhalation

ERV

Expiratory reserve volume: the maximal volume of air that can be exhaled from the end-expiratory position

IRV

Inspiratory reserve volume: the maximal volume that can be inhaled from the end-inspiratory level

IC

Inspiratory capacity: the sum of IRV and TV

IVC

Inspiratory vital capacity: the maximum volume of air inhaled from the point of maximum expiration

VC

Vital capacity: the volume of air breathed out after the deepest inhalation

FRC

Functional residual capacity: the volume in the lungs at the end-expiratory position

RV/TLC%-Residual volume expressed as percent of TLC

VA

Alveolar gas volume

VL

Actual volume of the lung including the volume of the conducting airway.

FVC

Forced vital capacity: the determination of the vital capacity from a maximally forced expiratory effort

should be same as VC

FEVt

Forced expiratory volume (time): a generic term indicating the volume of air exhaled under forced conditions in the first t seconds

FEV1

Volume that has been exhaled at the end of the first second of forced expiration

FEFx

Forced expiratory flow related to some portion of the FVC curve; modifiers refer to amount of FVC already exhaled

FEFmax

The maximum instantaneous flow achieved during a FVC maneuver

FIF

Forced inspiratory flow: (Specific measurement of the forced inspiratory curve is denoted by nomenclature analogous to that for the forced expiratory curve. For example, maximum inspiratory flow is denoted FIFmax. Unless otherwise specified, volume qualifiers indicate the volume inspired from RV at the point of measurement.)

PEF

Peak expiratory flow: The highest forced expiratory flow measured with a peak flow meter

MVV

Maximal voluntary ventilation: volume of air expired in a specified period during repetitive maximal effort